"Go forth, light and heavy, and strive with your money and your lives in the path of God," the Hamas leader added.
Issa was reportedly hiding in Nusirat, in central Gaza, at the time of the strike, and it is unclear whether the Hamas leader was killed in the event.
According to a report on Channel 13, Israel and the US have recently been discussing a plan for the exile of senior Hamas members as part of a wider deal.
According to some estimations, it is possible that Sinwar has surrounded himself with hostages, used as human shields.
Hagari also said that "Hamas's military framework in the northern Gaza Strip has been completely dismantled," and that the photo of Deif was found on a computer that was seized in the Strip.
Hamas has made it clear in recent days that it does not care what the IDF does to Khan Yunis and southern Gaza any more than it did to northern Gaza.
The IDF demolished a massive Hamas tunnel network beneath Gaza City • The UN Security Council passes a resolution intended to help bring more humanitarian aid into the Gaza Strip.